Wireless Impedance-based Structural Health Monitoring of Civil Structures using Smart PZT Interface Technique
- Abstract
- The goal of this dissertation is to develop a smart PZT interface technique for wireless impedance-based structural health monitoring (SHM) of civil structures. The following approaches are implemented to achieve the goal. Firstly, theories of the impedance-based damage detection method are outlined. Secondly, a smart PZT interface technique is developed for predetermining effective frequency bands in impedance monitoring practices. Thirdly, the applicability of the smart PZT interface technique is experimentally evaluated for the wireless impedance-based SHM of civil structures. Fourthly, the sensitivity of impedance signatures via the smart PZT interface is analyzed with regards to the essential parameters such as the geometry of the PZT interface and the location of damage. Fifthly, the compensation of temperature effects on impedance monitoring via the smart PZT interface is experimentally investigated. Finally, the PZT interface technique is combined with a model updating approach to quantitatively estimate the damage severity in structural connections. From the experimental and numerical evaluations, the smart PZT interface technique is found promising for the wireless impedance-based SHM of civil structures.
- Issued Date
- 2017
- Awarded Date
- 2017. 2
- Type
- Dissertation
- Keyword
- Structural Health Monitoring
- Publisher
- 부경대학교 대학원
- Affiliation
- Deparment of Ocean Engineering, Pukyong National University
- Department
- 대학원 해양공학과
- Advisor
- 김정태
- Table Of Contents
- CHAPTER 1 INTRODUCTION 1
1.1 Background 1
1.1.1 Structural Health Monitoring of Civil Structures 1
1.1.2 Impedance-based Structural Health Monitoring 3
1.1.3 Wireless Impedance Sensing Technology 6
1.1.4 Interface-based Impedance Monitoring 10
1.1.5 Temperature Effects on Impedance Monitoring 12
1.2 Research Needs on Wireless Impedance-based SHM 15
1.3 Objective Statement 18
1.4 Organization of Thesis 19
CHAPTER 2 THEORIES OF IMPEDANCE-BASED DAMAGE DETECTION METHOD 22
2.1 Overview 22
2.2 Fundamentals of Piezoelectric Technology 22
2.2.1 Piezoelectric Materials 22
2.2.2 Piezoelectric Sensors and Actuators 24
2.3 Basic Theories of Impedance-based Damage Detection 26
2.3.1 Genesis of Impedance-based Technique 26
2.3.2 Effective Frequency Bands 28
2.3.3 Statistical Damage Classification 29
CHAPTER 3 DEVELOPMENT OF SMART PZT INTERFACE TECHNIQUE 33
3.1 Overview 33
3.2 2-DOF Impedance Model 33
3.2.1 2-DOF Impedance Model for PZT Interface-Host Structure 33
3.2.2 Feasibility Verification of 2-DOF Impedance Model 36
3.3 Prototype Design of PZT Interface 41
3.3.1 Design of PZT Interface based on Local Dynamic Characteristics 41
3.3.2 Feasibility Verification of PZT Interface Prototype 53
CHAPTER 4 EXPERIMENTAL EVALUATION OF SMART PZT INTERFACE TECHNIQUE 60
4.1 Overview 60
4.2 Experimental Evaluation on Tendon-Anchorage System 60
4.2.1 SHM of Tendon-Anchorage System 60
4.2.2 Smart PZT Interface for Tendon-Anchorage System 63
4.2.3 Experiments on Tendon-Anchorage System 67
4.2.4 Impedance-based Prestress Force Monitoring 70
4.3 Experimental Evaluation on Bolted Girder Connection 75
4.3.1 SHM of Bolted Girder Connection 75
4.3.2 Smart PZT Interface for Bolted Girder Connection 76
4.3.3 Experiments on Bolted Girder Connection 77
4.3.4 Impedance-based Bolt-loosening Monitoring 82
CHAPTER 5 ANALYSIS OF SMART PZT INTERFACE’S GEOMETRY 88
5.1 Overview 88
5.2 Experimental Analysis of PZT Interface’s Geometry 88
5.2.1 Experimental Setup 88
5.2.2 Effects of Interface’s Size on Impedance Signatures 91
5.2.3 Effects of PZT’s Size on Impedance Signatures 95
5.3 Numerical Analysis of PZT Interface’s Geometry 99
5.3.1 FE Modeling and Simulation Scenarios 99
5.3.2 Effects of Interface’s Size on Impedance Signatures 103
5.3.3 Effects of PZT’s Size on Impedance Signatures 106
5.3.4 Effects of Sensor and Bonding Defects on Impedance Signatures 109
CHAPTER 6 SENSING REGION CHARACTERISTICS OF SMART PZT INTERFACE 111
6.1 Overview 111
6.2 Sensing Region Characteristics of PZT Interface on Plate Domain 111
6.2.1 FE Modeling 111
6.2.2 Sensitive Zone based on Coupled Vibration 113
6.2.3 Sensing Distance of Impedance Signatures 115
6.2.4 Detectable Zone of Impedance Signatures 117
6.2.5 Damage Detectability with respect to Plate’s Thickness 119
6.3 Sensing Region Characteristics of PZT Interface on Steel Splice Plate 121
6.3.1 Experimental Setup 121
6.3.2 Experimental Analysis of Sensing Region 122
6.3.3 Numerical Analysis of Sensing Region 125
CHAPTER 7 COMPENSATION OF TEMPERATURE EFFECTS ON IMPEDANCE MONITORING VIA SMART PZT INTERFACE TECHNIQUE 136
7.1 Overview 136
7.2 Temperature-Effect Compensation Algorithms 136
7.2.1 PCA-based Algorithm 136
7.2.2 RBFN-based Algorithm 139
7.2.3 EFS-based Algorithm 142
7.3 Experiments on PSC Girder 143
7.3.1 Test-Setup of PSC Girder 143
7.3.2 Simulation of Temperature Variation and Prestress-loss Events 145
7.4 Impedance Monitoring in PSC Girder under Constant Temperatures 147
7.4.1 Impedance Responses for Prestress-loss Events 147
7.4.2 Prestress-loss Monitoring Results 148
7.5 Temperature Effects on Impedance Monitoring in PSC Girder 149
7.5.1 Temperature Effects on Impedance Responses 149
7.5.2 Impedance Monitoring without Temperature Compensation 153
7.6 Compensation of Temperature Effects on Impedance Monitoring 155
7.6.1 Temperature Compensation by PCA-based Algorithm 155
7.6.2 Temperature Compensation by RBFN-based Algorithm 160
7.6.3 Temperature Compensation by EFS-based Algorithm 165
7.6.4 Discussion on Robustness and Applicability of Algorithms 171
CHAPTER 8 QUANTITATIVE DAMAGE SEVERITY ESTIMATION VIA SMART PZT INTERFACE TECHNIQUE 173
8.1 Overview 173
8.2 Impedance Monitoring of Tendon-Anchorage 173
8.3 FE Model of Tendon-Anchorage 174
8.3.1 FE Modeling 174
8.3.2 Numerical Impedance Signatures 176
8.4 Quantitative Damage Severity Estimation of Tendon-Anchorage 176
8.4.1 Phase-by-Phase Model Updating Approach 176
8.4.2 Identified Contact Stiffness of Tendon-Anchorage 178
8.4.3 Quantitative Severity Estimation of Tendon-Anchorage Damage 182
CHAPTER 9 SUMMARY AND CONCLUSION 185
REFERENCES 188
CURRICULUM VITAE 199
ACKNOWLEDGMENTS 204
- Degree
- Doctor
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